Properly grounding a new control panel outlet

[RiderCoachLar]

So I'm adding a new exclusive outlet for my 30A control panel. It is connected by conduit to my house electrical panel in which I installed a 30A double-pole GFI breaker and ran 10 gauge wire. My question is this: do I need to pull a fourth (ground) wire from the panel to the outlet or is the outlet properly grounded through the conduit?

 

[bruce_the_loon]

Someone from the US will chime in soon with knowledge of the code requirements. South Africa requires a ground wire to be physically wired into each socket.

From my perspective, even if code would permit it. I would not rely on metal conduit for earthing, too easy for poor contact if joints aren't tight.

 

[day_trippr]

The National Electrical Code in 2020 still allows the use of metal raceways/conduit as safety ground as long as the entire run is uninterrupted (ie: don't stick a plastic box in the middle of the conduit run ) and both ends are bonded to their respective boxes (ie: at the load center and at the remote enclosure).

That said, articles in the NEC are not law unless the local governing body adopts them, so it's always wise to check with local regs...

Cheers!

 

[RiderCoachLar]

The National Electrical Code in 2020 still allows the use of metal raceways/conduit as safety ground as long as the entire run is uninterrupted (ie: don't stick a plastic box in the middle of the conduit run ) and both ends are bonded to their respective boxes (ie: at the load center and at the remote enclosure).

That said, articles in the NEC are not law unless the local governing body adopts them, so it's always wise to check with local regs...

Cheers!

The run is definitely uninterrupted. The “bonding” is where my issue is and my brewing partner and I have a difference of opinion. Is it worth risking a poor bond on either end? I just assume run a 4th wire and know 100% that I have a solid ground. Am I worrying about nothing or overthinking this?

 

[day_trippr]

You could certainly opt for a separate ground wire (make sure it's gauge-appropriate for the load rating * distance) and just put the whole thing out of mind forever. Still, there are specific bonding methods dependent on raceway/conduit style that if followed would obviate the need for a ground wire and might allay your concerns, saving the effort of threading another wire...

Cheers!

 

[Maxkling]

I’m here to say, you always pull a ground. Yes it’s possible to use the conduit as a ground in some instances, but IT IS BAD PRACTICE. Anyone who works with conduit on a regular basis has come across conduit that has pulled apart, it happens.

 

[mabrungard]

Is the cable already run?? If not, do use 4 wire cabling for anything related to wet areas.

 

[day_trippr]

I’m here to say, you always pull a ground. Yes it’s possible to use the conduit as a ground in some instances, but IT IS BAD PRACTICE. Anyone who works with conduit on a regular basis has come across conduit that has pulled apart, it happens.

BAD WORK fails.
If one follows the NEC it is entirely safe and practical, but it does require intelligent effort.
Use a rube, deal with the consequences, but that's true of everything, isn't it...

Cheers!

 

[Maxkling]

BAD WORK fails.
If one follows the NEC it is entirely safe and practical, but it does require intelligent effort.
Use a rube, deal with the consequences, but that's true of everything, isn't it...

Cheers!

I work in industrial environments, I know we are talking about a home , but your work can be great and pass. Then someone uses your run as a step and pulls an anchor out of the block wall and pops the coupling apart, or maybe a light tap with a fork lift. Even using rigid, there is always a weak point that fails. It's just not worth it IMO to not use a ground conductor.

But doing some research it seems it is somewhat a common practice, so both ways work.

 

[day_trippr]

Yeah, I think we can dismiss the apocryphal stuff in this case
Really, it comes down to whatever the OP is comfortable with, and if that means pulling a 4th wire it probably should be done and done...

Cheers!

 

[RiderCoachLar]

Appreciate all the responses. What I hear, loud and clear, is that the conduit should be able to supply a proper ground as long as it is installed properly, however, running a fourth ground wire will, with less question, do the same. I also hear that using a ground wire with conduit provides two ground sources, should one be ineffective. I think, for a few bucks worth of wire and a few minutes of time, my answer is very clear. Thanks again.

 

[Bobby_M]

I didn't see anyone ask.. Are you going to be using a 4 wire load (aka 240v/120v)? If not, you'll only need 3 wires Hot, Hot, Ground.

If you do need 120v on this run, hence the need for the neutral, I would pull a ground through the conduit if you can.

If you DO rely on conduit, you do at least have the GFCI as extra protection should the ground fail you.

 

[RiderCoachLar]

I didn't see anyone ask.. Are you going to be using a 4 wire load (aka 240v/120v)? If not, you'll only need 3 wires Hot, Hot, Ground.

If you do need 120v on this run, hence the need for the neutral, I would pull a ground through the conduit if you can.

If you DO rely on conduit, you do at least have the GFCI as extra protection should the ground fail you.

Yes, my control panel will be running a couple of 120v pumps and I WILL be pulling a ground wire through the conduit.